This invention relates to electronic package modules. More particularly, an apertured substrate is adhesively bonded to a support substrate. One or more semiconductor devices disposed within the apertures are bonded to the support substrate utilizing the same adhesive.
Adhesively sealed metal packages are frequently used to encapsulate semiconductor devices. One package is disclosed in U.S. Pat. No. 4,939,316 to Mahulikar et al, which is incorporated by reference herein in its entirety. The package has anodized aluminum base and cover components defining a central cavity. A semiconductor device is bonded either to the base or to a leadframe paddle. A leadframe is disposed between the base and cover and an adhesive, typically a thermosetting epoxy resin, bonds a central portion of the leadframe to both the base and the cover encapsulating the semiconductor device. Thin bond wires electrically interconnect the semiconductor device to an inner portion of the leadframe while an outer portion of the leadframe is electrically interconnected to an external device such as a printed circuit board.
As the size of semiconductor devices decreases and the need for faster operating devices increases, it is desirable to house multiple semiconductor devices on the same module. One such module is disclosed in U.S. Pat. No. 5,124,783 to Sawaya which discloses an insulating substrate adhesively bonded to a centrally positioned support substrate. Apertures formed in the insulating substrate permit direct bonding of semiconductor devices to the support substrate with a conductive adhesive such as a silver filled epoxy resin. This package requires separate conductive die attach adhesive preforms to be deposited for each semiconductor device with precise alignment of each preform and accurate control of the volume of adhesive. If too small a volume of adhesive is utilized the semiconductor device may disengage from the support substrate. If excess adhesive is present, the adhesive may extend over electrically active surfaces of the semiconductor devices interfering with wire bonding. The thermosetting epoxy die attach preforms are difficult to remove and then accurately reposition after cure to replace defective semiconductor devices. As the number of semiconductor devices on a module increases, the cost associated with a defective device greatly increases.
Another type of package for housing a plurality of semiconductor devices is disclosed in U.S. Pat. No. 5,121,293 to Conte. A nonconductive substrate is press fit over a metallic heat sink. The nonconductive substrate includes apertures for housing semiconductor devices and circuit traces for tape automated bonding electrical interconnection of the semiconductor devices. The semiconductor devices are positioned within the aperture and the apertures partially filled with a thermoplastic resin to support the semiconductor devices in close proximity to the metallic heat sink. While the use of the thermoplastic facilitates replacement of defective semiconductor devices, each aperture is separately filled, requiring accurate placement of the adhesive and accurate control of the adhesive volume.
There exists, therefore, a need for an electronic package module which is capable of housing a plurality of semiconductor devices which is both reworkable and does not require accurate control of adhesive placement or adhesive volume.